内蒙古乌兰浩特市索伦镇中二叠统哲斯组海相暗色泥岩有机地球化学特征

在对内蒙古索伦地区中二叠统哲斯组岩性特征、沉积环境和暗色泥岩油气地球化学特征研究的基础上，总结了烃源岩的有机质丰度、干酪根类型和热演化的特征。暗色泥岩累积厚度达640m。总有机碳(TOC)的含量在0.38%~1.78%之间，TOC大于0.6%的样品占98%。有机质类型为Ⅱ~Ⅲ型。Tmax在354~548℃之间，Ro平均值3.24%，表明干酪根演化进入高—过成熟阶段。研究中还发现，S1+S2(<0.2mg/g)和IH(<16mg/g·c)都很低。造成上述结果的原因是，烃源岩已经经历过极高的热演化和排烃过程，排烃发生在晚二叠世和早白垩世晚期。

Organic geochemistry characteristics of marine dark mudstone in the Middle Permian Zhesi Formation in Suolun area of Inner Mongolia,China

Based on the lithologic features, precipitation facie and organic geochemistry characteristics of dark mudstone of Middle Permian Zhesi Formation, the authors summarize organic matter abundance, kerogen type and thermal evolution characteristics. The total thickness of dark mudstone is 640m. The content of TOC is between 0.38-1.78%, and samples of TOC values more than 0.6% account for 98%. The kerogen type is dominated by Ⅱ-Ⅲ type, Tmax values are 354-548 ℃, and the average vitrinite reflectance is 3.28%, which shows that kerogen has turned into high-extra evolution stage.In the study we also found that S1+S2(<3.2mg/g) and IH(<16mg/g·c) are very low. The reason is generating rock of weathering, has lived through the thermal evolution and hydrocarbon expulsion. The hydrocarbon expulsion happened in Early Permian and Late Cretaceous.